From: Sandeep Patil sspatil@android.com Subject: mm: proc: smaps_rollup: fix pss_locked calculation

The 'pss_locked' field of smaps_rollup was being calculated incorrectly. It accumulated the current pss everytime a locked VMA was found. Fix that by adding to 'pss_locked' the same time as that of 'pss' if the vma being walked is locked.

Link: http://lkml.kernel.org/r/20190203065425.14650-1-sspatil@android.com Fixes: 493b0e9d945f ("mm: add /proc/pid/smaps_rollup") Signed-off-by: Sandeep Patil sspatil@android.com Acked-by: Vlastimil Babka vbabka@suse.cz Reviewed-by: Joel Fernandes (Google) joel@joelfernandes.org Cc: Alexey Dobriyan adobriyan@gmail.com Cc: Daniel Colascione dancol@google.com Cc: stable@vger.kernel.org [4.14.x, 4.19.x] Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

fs/proc/task_mmu.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-)

--- a/fs/proc/task_mmu.c~mm-proc-smaps_rollup-fix-pss_locked-calculation +++ a/fs/proc/task_mmu.c @@ -423,7 +423,7 @@ struct mem_size_stats { };

static void smaps_account(struct mem_size_stats *mss, struct page *page, - bool compound, bool young, bool dirty) + bool compound, bool young, bool dirty, bool locked) { int i, nr = compound ? 1 << compound_order(page) : 1; unsigned long size = nr * PAGE_SIZE; @@ -450,24 +450,31 @@ static void smaps_account(struct mem_siz else mss->private_clean += size; mss->pss += (u64)size << PSS_SHIFT; + if (locked) + mss->pss_locked += (u64)size << PSS_SHIFT; return; }

for (i = 0; i < nr; i++, page++) { int mapcount = page_mapcount(page); + unsigned long pss = (PAGE_SIZE << PSS_SHIFT);

if (mapcount >= 2) { if (dirty || PageDirty(page)) mss->shared_dirty += PAGE_SIZE; else mss->shared_clean += PAGE_SIZE; - mss->pss += (PAGE_SIZE << PSS_SHIFT) / mapcount; + mss->pss += pss / mapcount; + if (locked) + mss->pss_locked += pss / mapcount; } else { if (dirty || PageDirty(page)) mss->private_dirty += PAGE_SIZE; else mss->private_clean += PAGE_SIZE; - mss->pss += PAGE_SIZE << PSS_SHIFT; + mss->pss += pss; + if (locked) + mss->pss_locked += pss; } } } @@ -490,6 +497,7 @@ static void smaps_pte_entry(pte_t *pte, { struct mem_size_stats *mss = walk->private; struct vm_area_struct *vma = walk->vma; + bool locked = !!(vma->vm_flags & VM_LOCKED); struct page *page = NULL;

if (pte_present(*pte)) { @@ -532,7 +540,7 @@ static void smaps_pte_entry(pte_t *pte, if (!page) return;

- smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte)); + smaps_account(mss, page, false, pte_young(*pte), pte_dirty(*pte), locked); }

#ifdef CONFIG_TRANSPARENT_HUGEPAGE @@ -541,6 +549,7 @@ static void smaps_pmd_entry(pmd_t *pmd, { struct mem_size_stats *mss = walk->private; struct vm_area_struct *vma = walk->vma; + bool locked = !!(vma->vm_flags & VM_LOCKED); struct page *page;

/* FOLL_DUMP will return -EFAULT on huge zero page */ @@ -555,7 +564,7 @@ static void smaps_pmd_entry(pmd_t *pmd, /* pass */; else VM_BUG_ON_PAGE(1, page); - smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd)); + smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd), locked); } #else static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, @@ -737,11 +746,8 @@ static void smap_gather_stats(struct vm_ } } #endif - /* mmap_sem is held in m_start */ walk_page_vma(vma, &smaps_walk); - if (vma->vm_flags & VM_LOCKED) - mss->pss_locked += mss->pss; }

#define SEQ_PUT_DEC(str, val) \ _